[SOLVED] How do you test a PSU?
- Thread starter joe pau
- Start date
SilverLeaf
Well-Known Member
- Reaction score
- 152
- Location
- US
I don't bother testing PSU's. For me, it's quicker and easier just to keep a few new PSU's handy, and do a quick swap out if I suspect a bad unit. If it solves the problem, great. If not, then I have ruled out a bad PSU and need to investigate further. The only time I have run into problems is with some of the oddball PSU's for some of the SFF cases (i.e. small Dell Optiplexs and such).
allstarit
Well-Known Member
- Reaction score
- 462
- Location
- Melbourne Australia
I have a coolermaster psu tester off ebay it can tell you if its not working however as silverleaf said above it is easier to have another psu in your kit to swap out if need be.
glricht
Well-Known Member
- Reaction score
- 805
- Location
- Zephyrhills, Florida
You can still test the PSU for the SFF cases. Just disconnect the orig PSU from the MB, take a test PSU and lay it onto the orig PSU and connect it to the MB and see if the PC turns on. It's not an end-all test, but you'll get a feel for the status of the orig PSU.
ohio_grad_06
Well-Known Member
- Reaction score
- 581
Agreed, I just keep a psu for testing, then if I suspect psu, plug in my test psu, if it acts normal, I recommend replacement.
Other thing about a psu tester, a psu tester may not tell you the ratings of a psu under load.
Other thing about a psu tester, a psu tester may not tell you the ratings of a psu under load.
gikstar
Well-Known Member
- Reaction score
- 410
- Location
- Ventura, California
That works for those SFF systems that have a standard 20/24 pin connector but a number of then have a tiny connector and you need to have one of those on hand also.
I used my tester on a power supply that someone was selling on Craigslist just the other day... fried my tester. I passed on that power supply.
I use a Coolmax Power Supply Tester that I got from Newegg, but as it's been said, it doesn't test under load but if it tests bad, you know it's bad, but if it tests good there is still a chance it could be bad under load.
I have noticed that some of the new power supplies that I've bought don't come up to the 12V as I would expect them to. Some of them show 11.5 or 11.6V
Also have a psu tester that detected some times a faulty one, but honestly i dont care it around as i prefer replace the psu from start. Most difficult problems to detect are when psu fail from stress and in that cases a tester wont help you. When the computer wont turn on or hdds wont spin is a face to face case of switching psu anyway.
I use a DVM to measure voltage but like Silverleaf and others say it's best to swap in a spare. I've seen too many PSU's fail intermittently. Rarely do I see a totally dead 5 or 12 Volt rail.
The last two PSU's I replaced produced the correct voltages but caused Windows to randomly reboot. The error logs usually state Win recovered from an unexpected shutdown. If the voltage dips for even a few cycles it's enough for the system to reboot or halt.
The last two PSU's I replaced produced the correct voltages but caused Windows to randomly reboot. The error logs usually state Win recovered from an unexpected shutdown. If the voltage dips for even a few cycles it's enough for the system to reboot or halt.
Thanks for all your replies. Definitely given me something to think about. I like the simplicity of "bring a test psu". Makes sense.
It does lead me to another question, How do you account for the differences in wattage or voltage? Do you carry multiple psu's or what?
Thanks again for your thoughtful answers.
It does lead me to another question, How do you account for the differences in wattage or voltage? Do you carry multiple psu's or what?
Thanks again for your thoughtful answers.
ohio_grad_06
Well-Known Member
- Reaction score
- 581
Wattage and voltages aren't a huge thing for me imo. I have a power supply that came out of my gaming pc. It is an ultra branded power supply, 650 watts, 36 amps on a single 12 volt rail.
It was powering my amd 8 core overclocked and Radeon 7850 until I replaced it. I figure that if it can power that during gaming for hours at a time I should be able to at midday power up almost any machine that comes in.
It was powering my amd 8 core overclocked and Radeon 7850 until I replaced it. I figure that if it can power that during gaming for hours at a time I should be able to at midday power up almost any machine that comes in.
gikstar
Well-Known Member
- Reaction score
- 410
- Location
- Ventura, California
Joe, best to have a power supply that has a 20+4 main connector, a 4+4 additional motherboard power connector, and a 6 pin and 6+2 pin video connector. I think that will hit all of the bases for a non-SFF computer.
I test the power supplies from all of the discarded/upgraded systems we end up with and if I do nothing else with the system I pull the power supply and keep it for an emergency fix.
If we are called out to a job and suspect that it may be a bad power supply in advance, I throw my box of power supplies in the minivan and take it with me.
Minivan... good investment. I can take the rear seats out and transport an air-conditioned server rack in there.
I test the power supplies from all of the discarded/upgraded systems we end up with and if I do nothing else with the system I pull the power supply and keep it for an emergency fix.
If we are called out to a job and suspect that it may be a bad power supply in advance, I throw my box of power supplies in the minivan and take it with me.
Minivan... good investment. I can take the rear seats out and transport an air-conditioned server rack in there.
